Is it permissible for a husband to prevent his wife from visiting her sister and to swear an oath against her?

Question : Shaykh Muhammad, we have a caller on the line. She says she is a woman with seven children, and her husband has sworn an oath that she will not speak to her elder sister, nor visit them, and that she will cut off ties with them. Is this permissible for him? And is it permissible for her to fulfill her husband's wish?

Answer : If the husband only swore an oath against her because when she goes to her sister, she ruins her for him, then he has the right to prevent her from visiting her sister, because he is thereby repelling harm from himself. And I said that while I do not like saying it, but the reality is that some relatives ruin the wife for her husband. For example, they say, "So-and-so buys this and that for his wives, and goes out with his wives for leisure trips, for 'Umrah and Hajj, and the like." Do they ruin the woman for her husband? These people, may Allah protect us from them, have committed a great sin, and they have become like the sorcerers who separate a man from his wife. The husband has the right to prevent her from visiting them. If someone asks, "How does he know that they have ruined her for him?"
The answer is that he knows that when she goes to them, she goes with an open heart, enchanted by her husband, but when she returns, she returns contracted, not restraining her husband except on the tip of her nose, and she complains about him and the like. However, if no harm comes to him from her visiting her relatives, then it is not permissible for the husband to prevent her from the customary visitation, due to the saying of Allah the Exalted: . And because relatives have a kinship tie that must be maintained. For this reason, a person must fear Allah the Exalted in his dealings with...
He treats those under his authority from among women, and he treats them as he would like to be treated. Similarly, every person must treat people as he would like to be treated. In other words, if you want to treat a person in a certain way, look at whether you would be satisfied if a person treated you in that same way. If you see that you would be satisfied, treat him that way; otherwise, do not treat him in a way that you dislike people treating you with. Yes. May Allah reward you.